Contribution of Various Sensory Inputs to Vertical Stance and Locomotion in Humans: Robust Assessment with Stabilography and Motion Videocapture

The purpose of this study was to evaluate reliability of basic parameters obtained with conventional stabilographic tests, and step characteristics recorded with motion videocapture, for fast robust assessment of the contribution of the vestibular system, vision, and proprioception to vertical stance and walking in healthy subjects. The contribution was computed as "weight coefficients" of each of the sensory input to the net motor outcome (the body balance at easy vertical stance and locomotion) at the conditions with deprivation of either vision (Romberg's test) or proprioception ("foot reaction" test), or both vision and proprioception. We found, that during easy vertical stance tested with stabilography, only the path length of the center of pressure presented relevant data. It allowed to estimate the contribution of the proprioception as cal. 0,5, while vision and the vestibular system both contributed roughly with 0,25. During walking, the vestibular system's contribution was 0,7 - 1,0 of the net share, while that of vision was negligible. These data generally correspond with the results obtained with more precise "science-intensive" methods. As such, conventional stabilography at various sensor-deprivation conditions could have had potential to assess, predict and prevent motor disorders.